A new USB specification that will offer faster speeds and is intended to simplify things is still being hammered by the USB Promoter Group, the standards body that oversees all things USB. It's called "USB4" (no space), and there should be an official spec relatively soon. What about actual retail products, though?
Our friends at Anandtech asked the USB Promoter Group (USB-IF) that very question at Computex. The response was that progress on the draft spec is proceeding at a fast pace, and that retail products supporting USB4 will be available by the end of next year.
There's a bit to digest there, and before we get to it, let's have a look at where USB stands currently. It's become a bit of a confusing mess with the introduction of the USB 3.2 specification, which doubles the bandwidth over USB 3.1 by allowing for up to two lanes of 10Gbps operation, for 20Gbps total. However, the spec also absorbs all prior USB 3.x specifications, so it can actually refer to three different transfer rates:
- USB 3.2 Gen 1: 5Gbps
- USB 3.2 Gen 2: 10Gbps
- USB 3.2 Gen 2x2: 20Gbps
As we have covered before, it gets even messier when factoring in the SuperSpeed marketing terms.
"SuperSpeed Plus, Enhanced SuperSpeed, and SuperSpeed+ are defined in the USB specifications, however these terms are not intended to be used in product names, messaging, packaging or any other consumer-facing content," USB-IF says.
USB-IF wants manufacturers to use the following marketing terms:
- USB 3.2 Gen 1: SuperSpeed USB
- USB 3.2 Gen 2: SuperSpeed USB 10Gbps
- USB 3.2 Gen 2x2: SuperSpeed 20Gbps
On top of all that, this is not the first time that USB names have changed. USB 3.2 Gen 1 used to be called USB 3.1 Gen 1, and prior to that it was USB 3.0. Confused? It's hard not to be. Here's a breakdown of past and present USB specs, and the name changes that have followed, where applicable:
- USB 1.1 ---> still USB 1.1 (Full Speed)
- USB 2.0 ---> still USB 2.0 (High Speed)
- USB 3.0 ---> USB 3.1 Gen 1 ---> USB 3.2 Gen 1 (SuperSpeed)
- USB 3.1 Gen 2 ---> USB 3.2 Gen 2 (SuperSpeed 10Gbps)
- USB 3.2 Gen 2x2 (SuperSpeed 20Gbps)
One thing I haven't talked about with any of the previous USB specs is the type of connectivity, and specifically the use of Type-A connectors (the ones on most of your USB devices that you inevitably try to plug in upside down on the first attempt) and Type-C (a smaller, reversible connector). And then there is Thunderbolt support—some USB-C devices have it, some don't.
Now that you're probably thoroughly confuzzled, let's circle back to USB4, which for some reason is not called USB 4 (with a space) or USB 4.0. Naming aside, USB4 will only use Type-C connectors. Furthermore, it integrates Thunderbolt 3 into the spec, so that's one less thing to have research, or guess. And as for speed, it will again double the bandwidth, from 20Gbps (10Gbps per lane) to 40Gbps (20Gbps per lane).
Though USB-IF thinks it will finalize the USB4 spec this summer, with retail USB4 devices showing up next year, it will take some time—probably years—for USB4 to permeate the PC landscape in a meaningful way. There are just too many existing USB devices in the wild for USB4 to storm the castle overnight.
That said, USB4 is a welcome evolution of USB, and will be worth waiting for.